Automatic bucket control



1964 F. A. SCHICK ETAL 3,161,307

AUTOMATIC BUCKET CONTROL Filed Oct 24, 1965 2 Sheets-Sheet l Jam gphplom 2 4 .44 /M- 2 Sheets-Sheet 2 Dec. 15, 1964 F. A. SCHICK ETAL AUTOMATIC BUCKET CONTROL Filed Oct 24, 1965 wk w United States Patent ()filice 3,161,3(17 Patented Dec. 15, 1964 3,161,367 AUTOMATIC BUCKET CONTROL Frederick A. Schick and Ian Gordon, Springfield, Ill., assignors to Allis-Chalmers Manufacturing Company, Milwaukee, Wis.

Filed Get. 24, 1963, Ser. No. 318,741) 4 Claims. (Cl. 214-140) This invention relates to an automatic bucket control for a material handling machine such as a tractor shovel.

It is an object of this invention to provide a means for releasably maintaining the control valve in its bucket return position until the bucket has moved to a loading position at which time the valve is automatically returned to neutral.

It is a further object of this invention to provide an automatic bucket control mechanism for returning a control valve to neutral from its bucket return position upon the bucket reaching a loading position wherein the position of the bucket is sensed by an element connected for movement with the bucket.

It is a further object of this invention to provide an automatic bucket control of the type hereinbefore outlined which is substantially insensitive to the vertical swinging movement of the structure supporting the bucket.

These and other objects and advantages will be apparent to those familiar with the art upon reading the following description in conjunction with the drawings in which:

FIG. 1 is a side view of a tractor shovel in which this invention is incorporated;

FIG. 2 is a partial section view showing the hydraulic control valve for the bucket control jack;

FIG. 3 is a top view of the automatic bucket control of this invention;

FIG. 4 is a side view of the automatic bucket control shown in FIG. 3;

FIG. 5 is a side View similar to FIG. 4 showing the control valve linkage resiliently detented in its bucket return position.

Referring to FIG. 1, the tractor shovei 11 has a tractor chassis or support 12 to which an intermediate supporting structure is connected for vertical swinging movement. The structure 19 includes a boom 13 pivotally connected at its rear end by a pivot on a transverse axis 14. Only one of two booms 13 is illustrated. The front ends of the pair of booms 13 have pivotally connected thereto on axis 17 a material handling or load carrying attachment in the form of a bucket 16. The structure 1% includes means for pivoting the bucket from the loading position illustrated in FIG. 1 to a dumping position which includes a bucket control linkage. The bucket control linkage includes a forward link 18, an intermediate lever 19 and a double acting hydraulic jack 21 comprised of a pair of relatively extensible and contractible elements in the form of a cylinder 22 and a piston having a piston rod 23. The rear end of the cylinder 22 is pivotally connected to the support 12 by a pivot on a transverse axis 24.

A control valve 26 for the jack 21 is mounted on top of a hydraulic reservoir 27 and suitable conduits 36, 37 interconnect the valve 26 and jack 21. A manually operable linkage 28 is provided at the operators station for operating the bucket control valve 26.

Referring to FIG. 2, the bucket control valve 26 may be of any suitable construction having a neutral or hold position and a pair of actuating positions for extending and contracting the hydraulic jack 21. A centering mechanism 31 is provided for a shiftable flow control element or spool 32 of the valve 26 to resiliently bias the spool 32 in its neutral position in which illustrated. In the neutral position of the control valve the jack supply ports 33, 34 which are connected to hoses 36, 37, respectively, are blocked. When the spool 32 i moved to the left, fluid under pressure will be delivered from chamber 35 to port 34 and thence to conduit 37 to expand the jack 21.

Referring to FIGS. 3 and 4, the manually operated valve control linkage 28 includes a lever 29 pivotally connected to the reservoir 27 by a pin 30 secured to a pair of brackets 42, 43. The lever 29 includes an arm 44 extending rearwardly and pivotally connected to a rod 46, which in turn is connected to one leg of a bell crank 47. The other leg of the bell crank 47 is connected to a rod 48 pivoted at its rear end to the valve spool 32. The bell crank 47 is pivoted by a pin 51 to a bracket 52 on the reservoir 27.

When the control lever 29 is moved to its return position as illustrated in dash lines in FIG. 4, it shifts the position of a detent element 56 to the left. A rod 57, to which element 56 is secured, is pivotally connected to the control lever 29 and to a free swinging lever 58 which in turn is pivotally connected by a pin 59 to the support 12. The detent element 56 has a tapered abutment surface 61 which is in abutable relation with a complementary tapered abutment surface 62 formed on a rotatable detent element in the form of a bell crank 63 pivotally connected by a pin 64 to support 12. The bell crank 63 has a second tapered surface 66 which serves as a camming surface abutable with a carnming surface 67 on the detent element 523. The detent element or bell crank 63 is resiliently biased toward a position of abutment with detent element 56 by a suitable spring 71 connected to an arm 72 on the bell crank 63 and to the support 12. The rotatable detent element 63 has an upstanding leg 76 which is pivotally connected on a transverse axis 77 to a link '78. Axis 77 swings in an are indicated by dash line 79. This are 79 passes through the axis 24 on which the double acting jack 22 is pivotally connected to support 12.

A pair of cam members, in the form of a bell crank 81 and an axially shiftable push rod 82, are secured to the relatively extensible and contractible elements 22, 23 of the double acting jack 21. The rod 82 is secured by a bracket 83 to the piston rod of jack 21 and is guided in a hollow tube 84 secured by brackets 86, 87 to the cylinder 22. The cam member 81 has it apex portion connected on an axis 88 to the bracket 86. A vertically disposed cumming surface 39 is formed on the rod 82 and extends in a plane in oblique relationship to a longitudinal vertical plane of the vehicle. As illustrated, the axis 88 is parallel to the plane on which camming surface 819 is formed. The camming surface on the camrning element 81 takes the form of a cylindrical surface on the periphery of roller 91 pivotally connected to one of the arms of camrning element 81. The other arm of the camming element is pivotally connected on a vertical axis 92 to the link 78.

The releasable detent means for the control valve 26 is such that the control valve is never positively locked, but rather it is releasably detented when moved to its return position. In such detented condition the operator can override the detent and move the lever from the return to neutral or dumping positions. When the double acting jack 21 has been expanded from the position in which it is illustrated in FIGS. 3 and 4 to that illustrated in FIG. 5, the cam member 82 will be moved forwardly sumciently to permit the camming element 81 to rotate clockwise, as viewed in FIG. 3, thus shifting the link 78 rearwardly and moving the detent element 63 counterclockwise as viewed in FIG. 4 to its detent position as illustrated in FIG. 5.

Assuming the operator has dumped the load from the load carrying attachment 16, the operator may place the lever 2 in the return position as illustrated in FIG. 5,

and in moving to this position the tapered surface 67 will cam against tapered surface 66 to permit the detent element 56 to move rearwardly into its detent position illustrated in FIG. 5 wherein tapered camming surface 62 is in abutting engagement with tapered camming surface 61. The resilient biasing spring 71 releasably urges the detent element 63 counterclockwise thus moving bell crank 81 into abutment with the rear end of tube 84 and in this condition the detent element is in the detenting position shown in FIG. 5.

By arranging the linkage so that the axis 77 is located closely adjacent to the axis 24, the detent mechanism is virtually unaifected by the vertical swinging of the supporting structure 10. This insures proper functioning of the automatic valve detent mechanism of this invention regardless of dumping height.

The embodiments of the invention for which an exclusive property or privilege is claimed are defined as follows:

1. In a material handling machine the combination comprising:

a support;

I a longitudinally extending boom;

means pivotally connecting the rear end of said boom to said support for rotation relative thereto about a transverse axis;

a load carrying attachment pivotally connected to the 'front end of said boom for pivotal movement between loading and dumping positions;

means for pivoting said attachment relative to said boom including i a double acting hydraulic jack having a pair of relatively extensible and contractible elements, a control valve mounted on said supporthaving a shiftable flow control member movable in opposite directions from a neutral position to dump and return positions; and centering means resiliently biasing said how control member toward its neutral position;

direction relative to said jack and the other of,

said cam members being shiftable transversely to the movement of said one cam member;

a pair of detent elements connected to said con- 'trol linkage and said other cam members, respectively, having tapered, camming surfaces in abutable relation to one another, and

means resiliently urging one of said detent elements into contact with said other detent elements whereby said camming surfaces engage one another to 'releasably maintain :said valve in itsreturn position until said attachment is moved 'by said jack to' its loading :position. '2. 'The structure set forth in claim 1 wherein said, ex-

:tensible and contractible elements .are -,a cylinder .and a' 3. The structure set forth in claim 2 wherein said cylinder is pivotally connected to said support on a transverse pivot axis, said one detent element is pivotally connected to said support in spaced parallel relation to said transverse pivot axis and wherein said detent means includes a link pivotally connected at one end to said other cam member and pivotally connected at its other end to said one detent element closely adjacent to said transverse pivot axis.

4. In a materialhandling machine the combination comprising:

a support;

a load carrying attachment;

a longitudinally extending intermediate structure connected to said support for vertical swinging movement by means including a transverse pivot, said intermediate structure including means connecting said attachment thereto for pivotal movement between loading and dumping positions,

a double acting hydraulic jack having a pair of relatively extensible and contractible elements, and

means connecting one attachment;

a control valve mounted on said support having a shiftable flow control member movable in opposite directions from a neutral position to dump and return positions and centering means resiliently biasing said flowcontrol member toward its neutral position;

conduits connecting said jack to said valve;

detent means for releasably holding saidcontrol valve in its return position when moved to the latter until said attachment has moved to said loading position including a longitudinally shiftable cam member connected to said attachment,

a rotatable cam member pivotally mounted on said intermediate structure, said shi-ftable cam member abutting .and pivoting said rotatable cam member when said attachment is moved to its load carrying position,

a first detent element connected to said valve presenting a first camming surface,

a second detent element pivotally connected to said support and presenting a second camming surface in abutable relation to said first cam- .ming surface,

a link pivotally connected to said second detent element on a transverse axis closely adjacent to :the axis of ,said transverse pivot and pivotally connected .to said second cam member, and

means resiliently urging said second detent element into abutment with said first detent element whereby said camming surfaces engage one another to releasably maintain said valve in its return position until said attachment is moved by :said jack to its loading position.

of said elements to said References Cited in the file of this patent UNITED STATES PATENTS 3,045,845 Hackett et al. July 24, 1962 

1. IN A MATERIAL HANDLING MACHINE THE COMBINATION COMPRISING: A SUPPORT; A LONGITUDINALLY EXTENDING BOOM; MEANS PIVOTALLY CONNECTING THE REAR END OF SAID BOOM TO SAID SUPPORT FOR ROTATION RELATIVE THERETO ABOUT A TRANSVERSE AXIS; A LOAD CARRYING ATTACHMENT PIVOTALLY CONNECTED TO THE FRONT END OF SAID BOOM FOR PIVOTAL MOVEMENT BETWEEN LOADING AND DUMPING POSITIONS; MEANS FOR PIVOTING SAID ATTACHMENT RELATIVE TO SAID BOOM INCLUDING A DOUBLE ACTING HYDRAULIC JACK HAVING A PAIR OF RELATIVELY EXTENSIBLE AND CONTRACTABLE ELEMENTS, A CONTROL VALVE MOUNTED ON SAID SUPPORT HAVING A SHIFTABLE FLOW CONTROL MEMBER MOVABLE IN OPPOSITE DIRECTIONS FROM A NEUTRAL POSITION TO DUMP AND RETURN POSITION: AND CENTERING MEANS RESILIENTLY BIASING SAID FLOW CONTROL MEMBER TOWARD ITS NEUTRAL POSITION: AND MANUALLY OPERATED CONTROL LINKAGE CONNECTED TO SAID CONTROL VALVE AND DETENT MEANS FOR RELEASABLY HOLDING SAID CONTROL VALVE IN ITS RETURN POSITION WHEN MOVED TO THE LATTER UNTIL SAID ATTACHMENT HAS MOVED TO SAID LOADING POSITION INCLUDING A PAIR OF CAM MEMBERS CONNECTED TO SAID EXTENSIBLE AND CONTRACTIBLE ELEMENTS, RESPECTIVELY, ONE OF SAID CAM MEMBERS BEING SHIFTABLE IN AN AXIAL DIRECTION RELATIVE TO SAID JACK AND THE OTHER OF SAID CAM MEMBERS BEING SHIFTABLE TRANSVERSELY TO THE MOVEMENT OF SAID ONE CAM MEMBER; A PAIR OF DETENT ELEMENTS CONNECTED TO SAID CONTROL LINKAGE AND SAID OTHER CAM MEMBERS, RESPECTIVELY, HAVING TAPERED CAMMING SURFACES IN ABUTABLE RELATION TO ONE ANOTHER, AND MEANS RESILIENTLY URGING ONE OF SAID DETENT ELEMENTS INTO CONTACT WITH SAID OTHER DETENT ELEMENTS WHEREBY SAID CAMMING SURFACES ENGAGE ONE ANOTHER TO RELEASABLE MAINTAIN SAID VALVE IN ITS RETURN POSITION UNTIL SAID ATTACHMENT IS MOVED BY SAID JACK TO ITS LOADING POSITION. 